add fload print function (#88)

src/observer/sql/expr/tuple_cell.cpp

@@ -16,6 +16,7 @@ See the Mulan PSL v2 for more details. */
 #include "storage/common/field.h"
 #include "common/log/log.h"
 #include "util/comparator.h"
+#include "util/util.h"
 
 void TupleCell::to_string(std::ostream &os) const
 {
@@ -24,7 +25,8 @@ void TupleCell::to_string(std::ostream &os) const
     os << *(int *)data_;
   } break;
   case FLOATS: {
-    os << *(float *)data_;
+    float v = *(float *)data_;
+    os << double2string(v);
   } break;
   case CHARS: {
     for (int i = 0; i < length_; i++) {

src/observer/util/util.cpp

+/* Copyright (c) 2021 Xie Meiyi(xiemeiyi@hust.edu.cn) and OceanBase and/or its affiliates. All rights reserved.
+miniob is licensed under Mulan PSL v2.
+You can use this software according to the terms and conditions of the Mulan PSL v2.
+You may obtain a copy of Mulan PSL v2 at:
+         http://license.coscl.org.cn/MulanPSL2
+THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
+EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
+MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
+See the Mulan PSL v2 for more details. */
+
+//
+// Created by wangyunlai on 2022/9/28
+//
+
+#include <string.h>
+#include "util/util.h"
+
+std::string double2string(double v)
+{
+  char buf[256];
+  snprintf(buf, sizeof(buf), "%.2f", v);
+  size_t len = strlen(buf);
+  while (buf[len - 1] == '0') {
+    len--;
+      
+  }
+  if (buf[len - 1] == '.') {
+    len--;
+  }
+
+  return std::string(buf, len);
+}

src/observer/util/util.h

+/* Copyright (c) 2021 Xie Meiyi(xiemeiyi@hust.edu.cn) and OceanBase and/or its affiliates. All rights reserved.
+miniob is licensed under Mulan PSL v2.
+You can use this software according to the terms and conditions of the Mulan PSL v2.
+You may obtain a copy of Mulan PSL v2 at:
+         http://license.coscl.org.cn/MulanPSL2
+THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
+EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
+MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
+See the Mulan PSL v2 for more details. */
+
+//
+// Created by wangyunlai on 2022/9/28
+//
+
+#pragma once
+
+#include <string>
+
+std::string double2string(double v);